As health care moves toward value-based approaches, it’s going to become increasingly important for physical therapists (PTs) and orthopedic surgeons (OSs) to pursue more “collaboration and consistency” when it comes to outcome measures used in total knee and hip arthroplasty cases, say authors of a new study.
That study, based on a survey of PTs in New England, found that many PTs relied on a range of performance-based outcome measures (PBOMs) and were less likely to use certain patient-reported outcome measures (PROMs) preferred by OSs—though that could be changing.
The study, which appears in Arthroplasty Today, is based on a survey of 122 PTs in Maine, Vermont, New Hampshire, Massachusetts, Rhode Island, and Connecticut. Researchers were trying to uncover differences between outcome measures commonly used by PTs, and those recommended for use in the American Joint Replacement Registry (AJRR), which authors of the study believe reflects measures most commonly used by OSs.
To qualify for inclusion in the survey, a PT must have treated patients undergoing total hip arthroplasty (THA) and/or total knee arthroplasty (TKA) in the past 5 years. PTs were asked to rate their current use of various outcome measures on a 4-point scale, from “not familiar” to “considerable experience.” The respondents further were asked to estimate their future use of the outcome measures, also based on a 4-point scale: “unable to rate,” “unlikely to use,” “likely to use,” and “will use and recommend.”
As for the outcome measures being evaluated, authors selected the Lower Extremity Function scale (LEFS), the numeric pain rating scale, Oxford Knee Score (OKS), Oxford Hip Score (OHS), EQ-5D quality of life measure, Knee Injury and Arthritis Outcome Score (KOOS), Hip Injury and Arthritis Outcome Score (HOOS), and the Western Ontario and McMaster Universities Arthritis Index (WOMAC) as the PROMs. For PBOMs, they asked PTs to rate walking speed, the 6-minute walk test, timed up-and-go (TUG), timed stair climb, Tinetti Mobility Test, Single-Leg Balance Test, and functional reach test.
Here’s what they found:
Respondents. The PTs included in the survey were mostly from mixed urban-rural areas (62.3%). Over half (53.5%) reported practicing in a private practice clinic; nearly 1 in 5 (18%) practiced in an outpatient clinical associated with an academic hospital or medical center. About a third of respondents (32.8%) reported 25 years’ experience or more; 17.2% reported between 10 and 14 years of experience, and 13.9% listed experience at between 15 and 19 years. Just over 42% of PTs surveyed said they’d treated 25 or fewer TKA/THA patients in the past year; nearly that many (38.9%) reported treating between 26 and 49 such patients during the past year.
Use of PROMs. The Numeric Pain Rating Scale and the LEFS were the measures most often cited by the respondents in terms of both current and future use of patient-reported data. Nearly all (99.2%) of the PTs reported current considerable experience with the pain rating scale, with 97.5% saying that they’d use and recommend the scale in the future. LEFS was also popular among the PTs, with 76.2% reporting considerable current experience and 77% supporting future use and recommendation.
Use of PBOMs. In the performance-based category, the PTs cited the Single-Leg Balance Test and the TUG as the most relied-upon measures. For the Single-Let Balance Test, 90.2% of respondents reported current use, with 87.7% saying they would use and recommend that test in the future. The TUG was even more popular, with 93.4% of the PTs reporting current use, and 85.2% reporting future use and recommendation.
The problem, according to the study’s authors, is that the PTs’ choices for PROMs don’t line up with the AJRR recommendations, which lean more toward general quality of life measures and specific joint measures such as the HOOS, KOOS, and Oxford knee and hip measures. “It is difficult to explain why [the surveyed PTs] prefer the LEFS,” authors write. “LEFS is easy to implement and broadly applicable to all lower extremity sites in various stages of disability, but is not specific to hip and knee osteoarthritis. The HOOS and KOOS are joint specific, including the [WOMAC] score, and have been shown to be more sensitive and responsive than the LEFS in total joint replacement. However, they take longer to administer.” [Editor’s note: APTA encourages the use of HOOS and KOOS for PTs participating in the Comprehensive Care for Joint Replacement bundled care model.]
And while authors point out that PROMs are probably more reflective of the direction health care is heading, they acknowledge that PBOMs such as TUG have their place, too.
“PROMs may overestimate patient mobility, especially in the immediate postoperative phase after both TKA and THA,” authors write. “Because [PTs] evaluate TJA [total joint arthroplasty] patients multiple times in the early postoperative period, they may utilize PBOM more frequently to avoid overestimation of function during the early phase of rehabilitation.” It’s an approach that the researchers say echoes recommendations from the Osteoarthritis Research Society International, which supports use of the sit-to-stand test, walking speed test, timed stair climb, 6-minute walk test, and TUG.
“PROMs and PBOMs also assess different time periods of recovery,” authors write. “PROMs generally assess a period of weeks of overall symptoms and function while PBOMs objectively measure function at a particular point in time. Both types of information are valuable in assessing patient recovery.”
Still, they argue, the evolution toward patient-centered care means that patient-reported outcomes are likely to become more important in the future. And while the PTs surveyed may not yet be fully in sync with this trend in THA and TKA measures, there are some signs of positive movement.
“This study showed that of the 16 outcome measures queried for clinical decision making, [PTs] indicated that they were less likely to use 4 of them in the future, all them PBOMs, and more likely to use 2 in the future, both PROMs,” authors write. “As surgeons and [PTs] work more closely, developing better understanding and consensus in the use of PROM and PBOM between surgeons and physical therapists will allow for improved assessment of TJA patient outcomes.”
Authors acknowledge several limitations of their study, including a low response rate and the lack of data indicating when the various measures were used in the course of treatment. Another potential limitation: a large proportion of PTs (42.6%) reported seeing fewer than 25 patients with THA or TKA annually.
Research-related stories featured in PT in Motion News are intended to highlight a topic of interest only and do not constitute an endorsement by APTA. For synthesized research and evidence-based practice information, visit the association’s PTNow website.